Installing the GPS4000
The GPS4000 gps time receiver system comprises a gps timing antenna and separate decoder module. Both the antenna and the decoder module should be securely fixed in place and the interconnecting cable connected, before connecting the decoder module to the MC Series master clock.
Positioning and installing the antenna:
The antenna should be installed externally, either on the roof or side of a building (GPS4000_WALL bracket required). For maximum reliability, the antenna should be positioned with a clear unobstructed view of the sky. For installations where an unobstructed view of the sky is not practical, the antenna should be installed with as large a view as possible of the sky towards the equator. Installing the antenna with a reduced view of the sky may result in increased synchronisation periods and slightly degraded timing accuracy.
The antenna should be mounted with the top of the dome facing directly upwards and secured using the stainless steel surface mount antenna bracket (or GPS4000_WALL bracket if supplied). Care should be taken to ensure the fixings used (not supplied) are suitable for the application.
If the antenna is to be installed in a location susceptible to a direct lightning strike, the installation of a surge protection device (GPS4000_SPD) inline between the GPS antenna and the decoder module is recommended.
Installing the decoder module:
The decoder module should be installed internally close to the point of antenna cable entry to the building. The enclosure should be secured in position using suitable fixings (not supplied) at the four 4.5mm (0.178”) case fixing points.
Antenna / decoder connection:
The system is supplied with a pre-terminated 8 metre TNC to TNC RG58CU coaxial cable for connection between the antenna and the decoder module. If required, this cable may be substituted for an alternative length of identical cable type up to a maximum of 25 metres. The cable should be connected to the compatible threaded socket on the underside of the GPS antenna and the socket on the decoder module.
It is important that the GPS antenna to decoder module connection is made prior to the master clock connection.